Various devices are incorporated in an electric apparatus. Usually, these devices, each of which is configured by stacking a plurality of modules, are accommodated in the electrical apparatus.
When the above-described modules are simply stacked, sufficient stability cannot be obtained, and hence a spacer is generally interposed between adjacent modules.
Here, as a device mounted on an electrical apparatus, there is, for example, a battery pack device used for a backup power source. This battery pack device is formed in such a manner that a plurality of battery modules, in each of which many general-purpose batteries are connected in parallel or in series to be able to provide a predetermined voltage and capacity, are combined for use. In this battery module, each general-purpose battery is fixed in a manner of being housed in a case, or being sandwiched between a pair of frames. The battery modules are stacked, for example, by providing a spacer therebetween. The battery pack device is formed in this way (see for example, Patent Document 1).